/*
 * Licensed to the Apache Software Foundation (ASF) under one

 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package com.neusoft.weixin.service.account;

import java.io.Serializable;

import javax.annotation.PostConstruct;

import org.apache.shiro.authc.AuthenticationException;
import org.apache.shiro.authc.AuthenticationInfo;
import org.apache.shiro.authc.AuthenticationToken;
import org.apache.shiro.authc.IncorrectCredentialsException;
import org.apache.shiro.authc.SimpleAuthenticationInfo;
import org.apache.shiro.authc.credential.AllowAllCredentialsMatcher;
import org.apache.shiro.authc.credential.CredentialsMatcher;
import org.apache.shiro.authc.credential.HashedCredentialsMatcher;
import org.apache.shiro.authz.AuthorizationInfo;
import org.apache.shiro.authz.SimpleAuthorizationInfo;
import org.apache.shiro.realm.AuthorizingRealm;
import org.apache.shiro.subject.PrincipalCollection;
import org.apache.shiro.util.ByteSource;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.beans.factory.annotation.Autowired;
import org.springside.modules.utils.Encodes;

import com.google.common.base.Objects;
import com.neusoft.weixin.entity.User;
import com.neusoft.weixin.service.CoreService;
import com.neusoft.weixin.web.token.UserToken;

public class ShiroDbRealm extends AuthorizingRealm
{
	private AccountService accountService;
	
	private static final Logger LOG = LoggerFactory.getLogger(ShiroDbRealm.class);
	

    public ShiroDbRealm() {
        super();
        //setCredentialsMatcher(new AllowAllCredentialsMatcher());
        //设置认证token的实现类，该处使用UsernamepasswordTken,也可自定义token，如果自定义token则需继承AuthenticationToken;
            setAuthenticationTokenClass(UserToken.class);
        //设置加密算法
        /**
         * 前台传入的明文与数据库中的加密数据进行比较，
         * new Digest()为自定义加密类，集成simpleCredentialsMatcher类，并重写doCredentialsMatch方法
         */
        //setCredentialsMatcher(new Digest());
       
   }
	
	/**
	 * 认证回调函数,登录时调用.
	 */
	@Override
	protected AuthenticationInfo doGetAuthenticationInfo(
			AuthenticationToken authcToken) throws AuthenticationException
	{
		UserToken token = (UserToken) authcToken;
		User user = null;
		byte[] salt = null;
		try {
			user = accountService.findUserByLoginName(token.getUsername());
		} catch (Exception e) {
			LOG.error(e.getMessage());
			return null;
		}

		salt = Encodes.decodeHex(user.getSalt());

		return new SimpleAuthenticationInfo(
				new ShiroUser(user.getId(),user.getUsername(),user.getAlias(),user.getRole())
				, user.getPassword(), ByteSource.Util.bytes(salt),
				getName());
	}
	
    /**
     * Asserts that the submitted {@code AuthenticationToken}'s credentials match the stored account
     * {@code AuthenticationInfo}'s credentials, and if not, throws an {@link AuthenticationException}.
     *
     * @param token the submitted authentication token
     * @param info  the AuthenticationInfo corresponding to the given {@code token}
     * @throws AuthenticationException if the token's credentials do not match the stored account credentials.
     */
	@Override
    protected void assertCredentialsMatch(AuthenticationToken token, AuthenticationInfo info) throws AuthenticationException {

		CredentialsMatcher cm = getCredentialsMatcher();
        if (cm != null) {
            if (!cm.doCredentialsMatch(token, info)) {
                //not successful - throw an exception to indicate this:
                String msg = "Submitted credentials for token [" + token + "] did not match the expected credentials.";
                throw new IncorrectCredentialsException(msg);
            }
        } else {
            throw new AuthenticationException("A CredentialsMatcher must be configured in order to verify " +
                    "credentials during authentication.  If you do not wish for credentials to be examined, you " +
                    "can configure an " + AllowAllCredentialsMatcher.class.getName() + " instance.");
        }			

	}


	/**
	 * 授权查询回调函数, 进行鉴权但缓存中无用户的授权信息时调用.
	 */
	@Override
	protected AuthorizationInfo doGetAuthorizationInfo(
			PrincipalCollection principals)
	{
		ShiroUser shiroUser = (ShiroUser) principals.getPrimaryPrincipal();
		SimpleAuthorizationInfo info = new SimpleAuthorizationInfo();

		// 将用户添加到授权中


		//设置url访问权限
		return info;
	}

	/**
	 * 设定Password校验的Hash算法与迭代次数.
	 */
	@PostConstruct
	public void initCredentialsMatcher()
	{
		HashedCredentialsMatcher matcher = new HashedCredentialsMatcher(
				AccountService.HASH_ALGORITHM);
		// SimpleCredentialsMatcher matcher = new SimpleCredentialsMatcher();
		matcher.setHashIterations(AccountService.HASH_INTERATIONS);

		setCredentialsMatcher(matcher);
	}

	@Autowired
	public void setAccountService(AccountService accountService)
	{
		this.accountService = accountService;
	}
	

	/**
	 * 自定义Authentication对象，使得Subject除了携带用户的登录名外还可以携带更多信息.
	 */
	public static class ShiroUser implements Serializable
	{
		private static final long serialVersionUID = -1373760761780840081L;
		public String userId;
		public String useralias;
		public String username;
		
		private String role;

		public ShiroUser(String userId, String username, String useralias,String role)
		{
			super();
			this.userId = userId;
			this.useralias = useralias;
			this.username = username;
			
			this.useralias = useralias;
			this.role = role;
			
		}
		
		
		
		public String getRole() {
			return role;
		}



		public void setRole(String role) {
			this.role = role;
		}



		public String getUseralias()
		{
			return useralias;
		}
		

		public void setUseralias(String useralias)
		{
			this.useralias = useralias;
		}

		public String getUsername()
		{
			return username;
		}

		public void setUsername(String username)
		{
			this.username = username;
		}




		public String getUserId()
		{
			return userId;
		}

		public void setUserId(String userId)
		{
			this.userId = userId;
		}
		

		
		

		/**
		 * 本函数输出将作为默认的<shiro:principal/>输出.
		 */
		@Override
		public String toString()
		{
			return username;
		}

		/**
		 * 重载hashCode,只计算loginName;
		 */
		@Override
		public int hashCode()
		{
			return Objects.hashCode(username);
		}

		/**
		 * 重载equals,只计算loginName;
		 */
		@Override
		public boolean equals(Object obj)
		{
			if (this == obj)
				return true;
			if (obj == null)
				return false;
			if (getClass() != obj.getClass())
				return false;
			ShiroUser other = (ShiroUser) obj;
			if (username == null)
			{
				if (other.username != null)
					return false;
			} else if (!username.equals(other.username))
				return false;
			return true;
		}
	}
}
